the number of constructed dams has been largely increased due to high demands of water supplies, and earth dams are the most common types since they are more compatible to the environment. nevertheless, the stability of these important structures during earthquakes has to be carefully evaluated and guaranteed. in the past, earth dams usually designed with pure clay core, but in recent decades t...

During October and November 1955 a bottom faunal study was undertaken at 19 localities in Buzzards Bay, Massachusetts. The number of animals ranged from 1,064 to 12,576/m2 with a mean number of 4,430. In comparison with certain other areas these numbers appeared small and seemed to be due to the relatively low concentrations of chemical nutrients and modest primary production of the region. Two...

X-ray phase analysis of clays is difficult because these materials generally consist of a mixture of different phases, i.e., mixed-layer minerals, individual clay minerals (non mixed-layer), and associated minerals, such as calcite and quartz. The analysis requires knowledge that presently is incorporated in a computer-based expert system. This expert system is capable of a) identification of a...

a greenhouse experiment was conducted during the growing seasons (2008/2009 and 2009/2010) to investigate the effects of water quality and soil amendments, irrigation methods and rates on tomato (solanum lycopersicon l. cv. red gold) yield and water use efficiency (wue). irrigation management treatments were fresh (0.86 ds m-1) and saline waters (3.6 ds m-1), surface and subsurface irrigation m...

A diverse flora has been discovered in a dark clay lens in upland gravel in southern Maryland near Brandywine. More than 49 taxa have been identified in the assemblage, which includes leaves, seeds, fruits, pollen, and a Taxodium (bald cypress) trunk. The vegetation is dominated by deciduous trees and vines. Four taxa are now absent from North America but survive elsewhere; one is extinct. A la...

The number of constructed dams has been largely increased due to high demands of water supplies, and earth dams are the most common types since they are more compatible to the environment. Nevertheless, the stability of these important structures during earthquakes has to be carefully evaluated and guaranteed. In the past, earth dams usually designed with pure clay core, but in recent decades t...

The water supply is the crucial problem of human beings in the world. Earth dams are usually the most important structures to store and manage the main sources: surface waters. The safety of earth dams in different conditions especially under earthquake loadings plays a vital role in sustainable developments. Recently, mixed-clay soil is widely used as water- seal material in the core of earth ...